1. Field of the Invention.
The present invention relates to universal joints.
2. Description of the Prior Art.
There have been proposed universal joints comprising an external cup-like element, and an internal element between which balls are interposed, the balls being held in slots of a spheroidal guide cage and being engaged in pairs of grooves in the internal and external element, the grooves being of generally toroidal form. Hitherto such joints generally have six balls engaged in like number of pairs of grooves.
An attempt has been made at making joints having fewer than six balls and fewer than six pairs of grooves in order to simplify machining, but this has hitherto been obtained only at the cost of additional machinings which are likely to weaken certain elements of the joint, in particular the cage.